tert‐Butyl Sulfoxides: Key Precursors for Palladium‐Catalyzed Arylation of Sulfenate Salts

Abstract The present report describes an efficient and clean generation of sulfenate salts (R 1 SO − ) by pyrolysis of readily available tert ‐butyl sulfoxides to give sulfenic acids (R 1 SOH) and traceless isobutene, followed by hydrogen abstraction with a weak inorganic base (K 3 PO 4 ). The relevance of this process was exemplified through an in situ palladium‐catalyzed cross‐coupling reaction with aryl halides/triflates leading to aryl sulfoxides. The operationally simple CS bond‐forming protocol developed uses Pd(dba) 2 as catalyst and Xantphos as ligand in toluene or a toluene/H 2 O mixture. Further extensions include the use of di‐ tert ‐butyl sulfoxide as an equivalent for sulfur monoxide dianion (SO 2− ) and the development of diastereoselective versions in the [2.2]paracyclophane and biaryl series. magnified image